The present disclosure relates to electronic amplifiers and amplification methods adapted to drive transducers and other electronic loads. Electronic amplifiers are also referred to in this disclosure as power amplifiers.
Power amplifiers typical amplify small electronic signals to a level and a power output sufficient to drive one or more transducers (i.e. a device that converts electrical energy into mechanical vibration) or other electronic loads (such as resistive loads). For example, audio power amplifiers can have power output sufficient to drive one or more loudspeakers, headphones, ear-canal phones (earbuds), direct current (DC) resistive loads or alternating current (AC) reactive loads. For example, a typical professional audio power amplifier for commercial use, can accept a professional line-level signal, for example a nominal line-level signal of 0.775 Volts root-mean-square (Vrms), and create an output capable of driving a hundreds or even thousands of Watts in one or more loudspeakers. Other power amplifiers are designed to amplify smaller signals, for example with a nominal level of 0.316 Vrms, and drive small amounts of power, for example 0.1 Watts to 2 Watts into headphones or earbuds. Other power amplifiers are designed amplify and/or drive other line-level signals into resistive or reactive loads.
Many power amplifier topologies exist for driving transducers and/or AC reactive and DC resistive loads. Some of these power amplifier topologies are designed to receive and amplify analog signals. These include class A, class AB, class B, class C, class D, class E, class F, class G, class DG, and class H, class S, class T amplifiers, as well has hybrids of these topologies. These topologies, among others, typically have various tradeoffs between distortion (signal linearity) and power efficiency. Other power amplifier topologies are designed to receive digital signals and output an analog signal capable of driving one or more transducers. For example, a power amplifier can use digital-to-analog conversion to convert a digital signal to an analog signal followed one or more of the various classes of amplifiers to amplify the analog signal.
With the advent of modern signal process devices and techniques, wide dynamic range signals are becoming more available. For example, it is not uncommon for digital audio signal paths to be 24 or 32 bits wide. This translates into a potential dynamic range (i.e. ratio of maximum signal level to noise-floor) of approximately 144 decibels (dB) for a 24-bit wide signal path and 192 dB of dynamic range for a 32-bit signal path.